Blow-off device.



v 6 m rn. ,5. m. if@ w m @5% m nv m MZ m m E. n. R .V E m M .ww wam .CFUumm .mmm

Dn w, m /W 6 o.

I M www anms PETERS cov. PHomumo NTTED STATES PATENT OFFICE'.

JOHN ROLSTON AND CHARLES YV. CRAMER, OF MINNEAPOLIS, MINNESOTA.

BLOW-OFF DEVICE.

SPECIFICATION forming part of Letters Patent N0. 689,231, dated December17, 1901.

Application nea June 27, 1901. sean No. 66.219. (Numan.)

To all whom t may concern,.-

Be it known that We, JOHN ROLSTONand CHARLES W. ORAMER, citizens of theUnited States, residing at Minneapolis, in the county of Hennepin andState of Minnesota, have invented certain new and useful Improvements inBlow-Oft Devices; and we do hereby declare the following to be a full,clear, and eX- act description of the invention, such as will enableothers skilled in the art to which it appert-ains to make and use thesame.

Our invention has for its object to provide an improved blow-off devicefor boilers; and to this end it consists otv the novel devices andcombinations'of devices hereinafter described, and defined in theclaims.

The invention is illustrated in the accompanying drawings, wherein likecharacters indicate like parts throughout the several views.

Figure 1 is a View, partly in side elevation and partly in section,showing a boiler equipped with one of our improved blow-off devices.Fig. 2 is an enlarged detail view in side elevation, showing theblow-off device removed. Fig. 8 is a section on the line 003mg of Fig.2. Fig. 4 is a section on the line x4 of Fig. 3, and Fig. 5 is a sectionon the line @c5 :t5 of Fig. 4.

The numeral 1 indicates an ordinary boiler, and the numeral 2 thesurrounding masonry. From the lower portion of the rear end of theboilerablow-o pipe 3 extends, as shown, rst downward and thenhorizontally rearward through the rear wall of the masonry. To the outerend of the primary section 3 of the blow-oft pipe is rigidly secured atwo-part valve-casing 4 5, -the sections of which, as shown, are drawntogether by screw-bolts 6. A packing-strip 7, placed between thesections 4 and 5, aords a steam-tight joint between said parts. Theinner surface of the casing-sectiou 5 aifords avalve-seat foraslidevalve8, carried at the free end of an oscillating arm 9, the hub of which iskeyed or otherwise secured on the inner end of an operating-stem 10,which stem works rotatively through the said casing-section 5. In thispreferred construction the said section 5 is provided with astuffing-box 1l, which coperates with a ange 12 on said stem 10 to clampthepacking material. The outer end of said stem 10 is shown as squaredat 13 to adapt it for the application of a wrench. The valve 8 is iatvon its working face, and on its back it is tapered or conical, for animportant purpose to be hereinafter noted. As shown, the said valve 8 isprovided with a square hub, which Works through a correspondinglyformedseat in the arm 9. The valve 8 is held tightly seated by means of a flatspring 15, which, as shown, is secured on the inner end of the stem 10by a nut 16.

By applyinga wrench or suitable tool to the square shank 13 of the stem10 the valve 8 may be vibrated between the positions indicated by fulland by dotted lines in Fig. 5. When the valve is in its normal position,(indicated by full lines in Figs. 4'and 5,) it closes adischarge-orifice 17 in the casing-section 5, which orifice opens into adischarge or supplemental blow-off pipe 18, which, as shown, is screwedinto the said section 5. The pipe 1S will be led to a distant point,where the steam-and-water discharge in the blowing-o action may besafely discharged.

The valve-case of the casing-section 5 is provided with an annulargroove or channel 19, which nearly or quite surrounds thedischarge-orifice 17, which the valve 8 opens and closes. Theclearing-groove 19 extends across the path of movement of the valve 8,and its edges serve to scrape into the said groove any rust or dirtwhich may stick to the face of the said valve. Under the movements ofthe valve 8 the groove 19 serves to scrape the face of the valve clearof all rust or sediment, so that the valve and its seat are caused towear evenly and maintain close joints.

In view of the beveled form of the outer face of the valve 8 alldeposits or incrustations within the casing and around lthe valve willbe forced away from the valve-seat with a wedge action and will bebroken up, so that they will be readily carried out through thedischarge-pipe under the blowing-olf action.

As is evident, the valve above described may be very quickly and easilyopened and closed without danger of being broken or displaced.

I-Iitherto a great dealof annoyance has been caused by the valves ofblow-off devices becoming corroded and stuck or clogged by theaccumulation of sediment. Furthermore,

loss of life has occurred in many instances by the breaking of the valveconnections, occasioned by pounding the stuck valves in order to releasethe same.

Our invention overcomes the above objections and dangers.

What we claim, and desire to secure by Let-v ters Patent of the UnitedStates, is as follows:

1. A bloW-oi device for boilers, comprising a valve-casing interposed inthe blow-off passage, a slide-valve Within said casing for opening andclosing the passage therethrough, a rotary stem projecting through saidcasing, and provided at its inner end with an arm for action on saidvalve and a spring applied to said arm and acting on said valve, to holdthe same seated, substantially as described.

2. A blow-off device for boilers, comprising a valve-casing interposedin the blow-oit passage, a slide-valve therein, provided with adischargebrice, a clearing-groove crossing the path of movement of saidvalve, in the vicinity of said orifice, and means for moving said valveto and from its closed position, substantially as described.

3..A blow-oft device, comprising a casing 4 5, the interior of thelatter affording a Hat valve-seat provided With a discharge-orifice 17,the beveled disk-like valve 8 with hub 14, a stem 10, projecting throughsaid casing, and provided at its inner end with the arm 9 in which thehub 14 of said valve 8 is loosely mounted, and the spring 15 applied tosaid arm 9, andacting on the hub of said valve to hold said valveseated, substantially as de.- scribed.

In testimony whereof we afiix our signatures in presence of twoWitnesses.

JOHN ROLSTON. CHARLES W. CRAMER.

Witnesses:

ELIZABETH KELEHER, F. D. MERCHANT.

